Messaging over mobile phone network for digital multimedia network

ABSTRACT

A method of distributing a message from a message administration service to a subscriber receiver decoder of a digital multimedia network comprises transferring a determined message for a determined receiver decoder from the message administration service to a point to point communication system distinct from the multimedia network. A destination point address of a receiver in the point to point communication system is determined, corresponding to the determined receiver decoder. The determined message is buffered in the point to point communication system, and retrieved at the determined receiver decoder from the receiver.

FIELD OF THE INVENTION

The invention relates to management of access rights in a digitalmultimedia network.

BACKGROUND OF THE INVENTION

FIG. 1 schematically illustrates an example of a digital multimedianetwork. A network 1 is used to exchange information between one or manybroadcast operators, represented in boxes 2 and 3, and subscribersrepresented in boxes 4 to 6. The network may for example be aterrestrial television broadcast network in which the broadcastoperators emit signals that are received by means of an aerial antennaby the subscriber. Another example of network may be a cable network, ora satellite transmission network.

Each broadcast operator may broadcast a number of digital multimediaservices to the subscribers. The multimedia services may for exampleinclude television programmes, radio programmes, and interactiveapplications.

Each subscriber has a receiver decoder that is used to receive themultimedia services and in some cases to process the received multimediaservices in order to render the multimedia services on a renderingdevice as appropriate. A television programme may for example berendered on a television, and an interactive application may need to beexecuted by a processing system of the receiver decoder and generateinteractivity with the subscriber.

Typically all digital multimedia services are received by allsubscribers. More generally, all information broadcast by the broadcastoperators over the network may potentially be received by allsubscribers.

It is known to restrict access to multimedia services by attributingaccess rights to the subscribers. Hence a subscriber may only accesssuch multimedia service for which he possesses corresponding accessrights. A higher degree of restricted access to the multimedia servicesmay be achieved by scrambling a service using a control word. In thiscase the subscriber may only access and unscramble the scrambled serviceif he possesses the control word.

Access right information may be broadcast to the subscribers 4-6 overthe network 1. Typically the control word is broadcast to allsubscribers using an Entitlement Control Message (ECM). However thecontrol word may only be extracted from the ECM if the subscriber hasaccess to an exploitation key that is periodically broadcast over thenetwork in an Entitlement Management Message (EMM).

The publication of the international application WO01/17249A1 DEUTSCHETELECOM AG concerns a method for releasing customer specificauthorisations using security modules in conditional-access systems forchargeable devices. WO01/17249A1 describes to transmit EMMs tosubscribers. A first possibility provides for transmitting an EMM usinga Public Switched Telephone Network (PSTN), a mobile phone network suchas a GSM network, or any other way of broadcast to transmit the EMM to acontrol device of a vendor. The vendor on turn uses the control deviceto transmit the EMM to a subscriber device in order to activate asubscription. The first possibility is said to be indirect because itrequires an intervention of an intermediate between a provider and thesubscriber, in this case the vendor. A second possibility provides fortransmitting the EMM directly by broadcast to the subscriber device. Ageographical localisation of the subscriber device may be effected byexploiting localisation data relative to a subscriber GSM device. A GSMnetwork provider has the possibility to determine a geographicallocalisation of a subscriber's GSM device if this device is switched on.The knowledge of the geographical localisation of the subscriber devicemay allow to restrict the broadcast of the EMM to a restrictedgeographical localisation, if at all possible. The second possibilityalso mentions an embodiment according to which to which the subscriberfirst calls the EMM provider by using his GSM phone and subsequentlyobtains the EMM by broadcast.

WO01/17249A1 further describes the possibility to use the GSM phonenetwork to transmit an EMM to a subscriber. However WO01/17249A1 advisesnot to use the GSM phone network for this purpose.

The publication Functional model of a conditional access system, EBUTechnical review, Winter 1995, describes in paragraph 7.2.1 that itwould be possible to establish a return path between a subscriber'sdecoder and a Subscriber Management System (SMS) using either the PSTNor a cable network, and to use this return path to transmit EMMs. Onereason for using a return path would be to reduce broadcast bandwidthconsumed by the broadcast of EMMs.

SUMMARY OF THE INVENTION

In a first aspect the invention provides a method for distributing amessage from a message administration service to a subscriber receiverdecoder of a digital multimedia network. A determined message for adetermined receiver decoder is transferred from the messageadministration service to a point to point communication system distinctfrom the multimedia network. A destination point address of a receiverin the point to point communication system is determined, correspondingto the determined receiver decoder. The determined message is bufferedin the point to point communication system, and the determined messageretrieved at the determined receiver decoder from the receiver.

Preferably the determined message is buffered at an emitter point in thepoint to point communication system, corresponding to the messageadministration service. A signal of availability is generated at thereceiver. On reception of the signal of availability an emission of thedetermined message is triggered, and the determined message is emittedto the receiver.

In a second aspect the invention provides a method for receiving adetermined Entitlement Management Message (EMM) at a determinedsubscriber receiver decoder in a digital multimedia network. Thedetermined subscriber receiver decoder is enabled to receive informationthrough a mobile phone communication network distinct of the digitalmultimedia network. A message containing at least the determined EMM isreceived in a mobile phone modem of the receiver decoder, the messagebeing addressed specifically to the mobile phone modem of the determinedreceiver decoder. At least the EMM is stored in a storage of the mobilephone modem.

In a third aspect, the invention provides a receiver decoder for adigital multimedia network, comprising a mobile phone modem operativelyconnected to the receiver decoder, and a destination point addressuniquely attributed to the mobile phone modem. The receiver furthercomprises a storage space in the mobile phone modem to store at least anEntitlement Management Message (EMM).

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be described in greater detail with reference tothe accompanying drawings, in which

FIG. 1 contains a schematic representation of a digital multimedianetwork,

FIG. 2 illustrates a broadcast and receiver system for a digitalmultimedia network,

FIG. 3 contains a schematic representation of a conditional accesssystem applied to a broadcast receiver system,

FIG. 4 illustrates an example of an Entitlement Management Message,

FIG. 5 contains a block diagram representing an example of a receiverdecoder,

FIG. 6 contains a schematic representation of an example of embodimentof the invention,

FIG. 7 contains a flowchart illustrating an example of embodiment of theinvention

DESCRIPTION OF THE PREFERRED EMBODIMENTS

System Overview

Same references will be used to reference same elements in the Figuresthroughout the description.

FIG. 2 contains a schematic illustration of a digital television system.On a side of a broadcaster, a signal compression system 100 compresses adigital signal stream (not shown) and outputs a compressed stream to amultiplexer 101. An example of compression is the well known MPEG-2standard, which is widespread in the field of digital televisionservices. The multiplexer 101 produces a transport stream of compressedsignals that is transmitted to a subscriber having a receiver decoder102. The transport stream is emitted using an antenna to a satellite 104and subsequently broadcast to a receiving antenna 105 that is connectedto an input of the receiver decoder 102. FIG. 2 illustrates a satellitetransmission system, but any other way of transmitting the transportstream from the side of the broadcaster to the subscriber may be used.

The receiver decoder 102 processes the received transport stream inorder to extract data, such as for example an audio/visual service or anapplication, and outputs resulting video and audio signals to arendering device, such as for example a television 106. In the presentexample the receiver decoder 102 may decode the compressed MPEG-2 streaminto a television signal output to the television 106.

Although a separate receiver decoder 102 is shown, the receiver decodermay also be an integral part of an digital television.

In a multichannel system, the multiplexer 101 may handle audio and videoinformation provided simultaneously by a plurality of sources. Inaddition to audio and video information, any other sort of information,e.g., messages or applications may be introduced in one or more of thechannels, interlaced with the audio and video information.

FIG. 3 illustrates the digital television system from FIG. 2 enhancedwith a number of security devices. For reasons of better readability,broadcast transmission features from FIG. 2 have been replaced by adotted arrow 200 in FIG. 2. A conditional access system 201 is connectedto the multiplexer 101. A further component of conditional access 202 isconnected to the receiver decoder 102. The conditional access system 201and the further component of conditional access 202 enable a securedaccess in the receiver decoder 102 to digital television servicesbroadcast by one or many broadcast suppliers. The further component ofconditional access 202 is completed by a daughter smartcard 203 that isinserted into an appropriate location of the receiver decoder 102. Thedaughter smartcard 203 carries information required to descramblescrambled messages related to available commercial offers. Theinformation may comprise subscription rights, one or more exploitationkeys extracted from received EMMs and one or more control wordsextracted from ECMs. Using the daughter smartcard 203 it is possible topurchase commercial offers by way of subscription or pay per view.

Digital services included in the digital data stream are scrambled at alevel of the multiplexer 101, under control of the conditional accesssystem 201. Typically, scrambling is done using a control word, thelatter being transmitted together with the scrambled digital servicesfor eventual descrambling. The control word itself is encrypted fortransmission, the encryption being done with an exploitation key.

The conditional access system 201 comprises a Subscriber AuthorizationSystem (SAS) 204, which is connected to one or a plurality of SubscriberManagement System(s) (SMS) 205. The SMS 205 and the SAS 204 may belinked for example using a TCP/IP link. Typically there is one SMS 205per broadcast operator, but it may happen that the SMS 205 is shared bymore than one broadcast operator.

The conditional access system 201 further comprises a first CipheringUnit 206 that makes use of a first Mother SmartCard 207, and isconnected to the SAS 204. The first mother smartcard 207 storesconfidential information that is used to encrypt data.

A second Ciphering Unit 208 that uses a Second Mother SmartCard 209 isconnected to the multiplexer 101.

Subscriber Management System

The SMS 205 includes a database that manages, amongst others, subscriberfiles, commercial offer data including pricing and special offers, payper view details, authorisation and consumption data.

The SMS 205 may be remote from the SAS 204.

The SMS 205 transmits messages to the SAS 204 relating for example to asubscriber's authorisations to view a digital service when such adigital service is requested by the subscriber, or to a pricing of adigital service acquired and to be paid by the subscriber.

On the other hand the SAS 204 may send messages to the SMS 205 relatingfor example to requests about a subscriber contact identification.

Entitlement Management Message (EMM)

The EMM is a message dedicated to an individual subscriber, or a groupof subscribers. This is in contrast with the ECM, which is generallydedicated to one or a determined number of scrambled digital service(s)rather than being dedicated to one or many subscribers.

Various specific types of EMMs are possible. In the following, 4examples of types of EMM will be described, namely individual group,audience and unique EMMs.

An individual EMM is dedicated to an individual subscriber, and maytypically be used in provision of a pay per view service. The individualEMM comprises a group identifier and a position of the individualsubscriber in the group.

A group EMM is dedicated to a group of subscribers, e.g. 256 individualssubscribers, and is typically used for administrating subscriptionservices.

An audience EMM is dedicated to an entire audience of individualsubscribers. The audience comprises all individual subscribers having asmartcard that bears a same operator identifier.

A unique EMM is dedicated to be addressed to a unique identifier of asmartcard.

FIG. 4 illustrates an example of a general form of an EMM. The EMM isimplemented as a series of digital data bits and comprises a header 400,an EMM proper 401 and a signature 402. The header 400 in turn comprisesa type identifier 403 that identifies the message as an EMM and alsoindicates the type of EMM, a length identifier 404 that gives a lengthof the EMM, an optional address 405 for the EMM, an operator identifier406, and a key identifier 407. The signature 402 is optional andprovides a number of checks against corruption of the data bits in theEMM.

The EMM proper comprises data relating to subscriber authorisation andto one or many exploitation keys.

Subscriber Authorization System (SAS)

Referring again to FIG. 3, the SAS 204 receives and processes messagesfrom the SMS 205. The SAS 204 generates messages acknowledging receiptof the messages generated by the SMS 204 and passes theseacknowledgement messages to the SAS 205.

The messages received from the SMS 205 concern for example a suspensionof a susbcriber's rights in case the subscriber failed to pay hissubscription fee, a modification of subscriber's rights in order to addor remove a commercial offer, or an addition of rights that are requiredto access a specific pay per view digital service.

The SAS 204 manages a database that stores a status for each subscriberpreviously declared by the SMS 205. According to the status and otherinformation received from the SMS 205, the SAS 204 generates one or moreEMMs at the intention of the subscriber's smartcard 203. The EMMs areciphered using the first ciphering unit 206.

In network systems known from prior art, the SAS 204 ensures that theEMMs are received by the subscriber by sending the EMMs cyclically tothe multiplexer 101 for broadcast to the subscriber. A frequency of thecycle depends of the type of EMM, and may typically have a value between30 seconds and 30 minutes.

The EMMs are sent to the multiplexer 101 through a device commonly knownas injector (not shown in FIG. 3). The injector is well known in the artand will not be described here any further.

Entitlement Control Message (ECM)

Referring again to FIG. 3, the multiplexer 101 typically contains ascrambler that is used to scramble digital services to be broadcast. Thescrambler generates a control word that will be used in the scramblingprocess, and transmitted together with the scrambled digital service tothe subscriber.

A digital service may also be subject to access criteria, which forexample associate the digital service to a determined commercial offer.The access criteria should match a subscriber's subscription to thedetermined commercial offer in order for the digital service to becomeaccessible to the subscriber.

Both the control word and the access criteria are inserted into an ECMthat is broadcast together with the scrambled digital service. Theinsertion is done by transmitting the control word and the accesscriteria to the second ciphering unit 208 where the ECM is generated,scrambled using an exploitation key stored in the second mothersmartcard 209 and transmitted back to the multiplexer 101.

The digital service is scrambled by the scrambler using the controlword. Subsequently the scrambled digital service and the scrambled ECMare broadcast to the subscriber.

Receiver Decoder

Referring to FIG. 5, an overview is given for various elements in anembodiment of the receiver decoder 102, shown here as functional blocks.

The receiver decoder 102 is sometimes also referred to as a Set Top Box(STB). The receiver decoder 102 comprises a central processor 500including associated memory elements. The central processor 500 isadapted to receive input data from a serial interface 501, a parallelinterface 502, a modem 503 and switch contacts 504 located on a panel ofthe receiver decoder 500.

The receiver decoder is further adapted to receive inputs from aninfra-red remote control 505 via a control unit 506, and comprises oneor many smartcard readers 507 and 508 that allow to read a banksmartcard 509 or the daughter smartcard 203. The daughter smartcard 203engages with the smartcard reader 507 and the further component ofconditional access 202, in order to supply the necessary control word toa demultiplexer/descrambler 510, and hence enable the encryptedbroadcast signal to be descrambled.

The decoder receiver 500 further comprises a conventional tuner 511 anda demodulator 512 to receive and demodulate the broadcast signal beforeprocessing by the demultiplexer/descrambler 510.

The decrypted signal at an output of the demultiplexer/descrambler 511is processed as appropriate by an audio decoder 513 and preamplifier 514before being made available at an audio output 515, and by a videodecoder 516, before being transmitted to a graphic processor 517 andencoder in a PAL/SECAM encoder 518 and made available at a video output519.

Cyclical Transmission of EMMs

As mentioned before in this specification, EMMs from prior art systemsare permanently broadcast to the subscribers in a carousel mode, i.e.,cyclically transmitted, over all broadcast means. This is done in orderto ensure that independently of a state of a receiver decoder and of ageographical location of the receiver decoder, as soon as the receiverdecoder is switched on it will be able to receive the related EMM for aforthcoming subscription period.

Using the cyclical transmission uses a relatively large amount ofbroadcast bandwidth. Moreover it is impossible to know if or when adetermined receiver decoder as received an EMM.

A cycle period of the EMM broadcast needs to be reasonably short inorder to avoid that a long waiting time occurs until reception of theEMM by a receiver decoder that has been switched off for an extendedperiod of time.

It is known to reduce the broadcast bandwidth required for broadcastingEMMs by using group EMMs that may reach more than one user.

In the well known DVB broadcast standard, an EMM is typically broadcastas a message having a specific determined identification number. Sincethe EMM may be received by anyone receiving the broadcast, it ispotentially feasible to analyse the messages received having thespecific determined identification number in order to gather informationabout the EMMs and a related security scheme. This may in some casesweaken the level of security of the broadcast system.

Transmission of EMMs Over a Mobile Phone Network

According to the present invention, the EMMs are transmitted to thesubscribers using a mobile phone network rather than the broadcastnetwork. The mobile phone network allows a point to point communication,i.e. a message may be transmitted from one emitter point to a singledestination point address.

Referring to FIG. 6 a system is shown in which EMMs are transmitted overa mobile phone network 600. The system in FIG. 6 is based on the systemshown in FIG. 3, and the receiver decoder 202 is based on the receiverdecoder shown in FIG. 3 and FIG. 5. For reasons of better readability anumber of elements shown in FIGS. 3 and 5 have not been represented inFIG. 6.

The SAS 204 transmits the EMMs to a mobile phone database 601 ratherthan transmitting the EMMs through an EMM injector to the multiplexer101. Each EMM is intended for at least one determined receiver decoder.The determined receiver decoder relates to an address in the mobilephone network, i.e. the destination point address, that is stored in themobile phone database 601. Accordingly, the mobile phone database allowsto retrieve the address for the determined receiver decoder whenreceiving the EMM from the SAS. The address will be used to send the EMMto the determined receiver decoder.

The EMM and the corresponding address of the determined receiver decoderare subsequently forwarded to the mobile phone network 600, i.e. to theemitter point of the mobile phone network, where a network managementsystem and a local cell transmitter (not shown) sends the EMM to amobile phone receiving modem 602 connected to or integral with thereceiver decoder 202, and having the corresponding address receivedtogether with the EMM.

The EMM remains buffered in the mobile phone network or the mobile phonereceiving modem until it is retrieved by the receiver decoder. Moreprecisely the EMM may remain stored at the level of the mobile phonenetwork 600 if the mobile phone receiving modem 602 is not available forreceiving messages. Once the mobile phone receiving modem 602 becomesavailable, i.e. the mobile phone receiving modem 602 generates a signalstating that it is available, the EMM is transmitted. The EMM remainsstored in the mobile phone receiving modem 602, until it is retrieved bythe receiver decoder. This is the case in particular when the receiverdecoder is switched off or down for other reasons.

Optionally the receiver decoder 202 comprises a SIM card reader 603adapted to read a SIM card 604. The SIM card 604 contains informationrequired to manage access rights for the mobile phone network, theaccess rights being used by the mobile phone receiving modem 602.

Advantageously the access rights for the mobile phone network may beincluded on the daughter smartcard (not shown) instead of the SIM card604.

The specific EMM is sent only once from the SAS 204 to the mobile phonedatabase 601 and network 600. The specific EMM remains in the mobilephone system and is only transmitted to the modem 602 when the latter isready to receive the specific EMM. If the specific EMM becomes outdatedby that time it may preferably be deleted and/or replaced without havingbeen previously sent to the receiver decoder 202.

Optionally the modem 602 may return a confirmation message to the mobilephone network after receiving the specific EMM. The confirmation messagemay comprise additional data such as specific receiver decoder data ordata related to the daughter smartcard in use with the receiver decoder202. An example of information comprised in the additional data may beobtained using one or a plurality of items out of the following list:status of the receiver decoder, status of the daughter smartcard,identification number(s), version of elements contained in the receiverdecoder. The transmission of the conformation message comprisingadditional data may provide a method that allows the broadcaster toverify parameters of the receiver decoder and detect a legal status ofthe receiver decoder, i.e., a possible illegal use of the receiverdecoder or the daughter smartcard.

The specific EMM may be transmitted to the modem 602 embedded in a smallmessage commonly known as SMS (Short Message Service, not to be confusedwith the Subscriber Management System) in the GSM mobile phone networks.The SMS may remain stored in a SMS server of the GSM mobile phonenetwork if the mobile phone receiver modem is not ready or available forreceiving messages.

As a result of the invention, the EMM injector known from prior art,which is used by the SAS to inject EMMs to the multiplexer, may beomitted.

Optionally the GSM modem 602 may also be used together with the receiverdecoder 202 to communicate over the mobile phone network 600 by emittingphone calls or establishing data connections. For this purpose thereceiver adapter 202 may comprise audio input and output devices 605,including a microphone.

It has become apparent that each EMM is sent uniquely to its associatedreceiver decoder using a network distinct from the broadcast network.Accordingly the invention uses no broadcast bandwidth as in prior art.The EMM may be sent over the mobile phone network at convenient timeswhen the network capacity is less used by conventional mobile phoneservices. As is well known in mobile phone networks, the informationsent to the mobile phone modem will only be transmitted inside ageographical area corresponding to a transmission cell in which thephone modem in located.

Advantageously the receiver decoder 202 need not explicitly initiate aconnection to the CAS 201 to receive an EMM.

Optionally the mobile phone modem 602 may be configured to always remainin reception not only of an EMM, but also of any other type ofinformation or incoming mobile phone service if required.

The system according to the invention improves security in that thespecific EMM is sent to one receiver decoder only. It becomes moredifficult to receive and listen to more than one EMMs as was the case inprior art.

The optional conformation messages improves security in the system, inthat the use of the EMM by a determined receiver decoder may beverified.

The mobile phone modem 602 has been described as a GSM modem. It is ofcourse possible to have any other type of modem depending on the mobilephone network's standard, e.g., GSM, GPRS, UMTS . . .

FIG. 7 shows a flowchart illustrating an embodiment of the invention. AnEntitlement Management Message EMM_(D1) intended for a receiver decoderD1 is transferred from the SAS to the Mobile Phone Network (MPN) in astep 700. In a next step 701 an address of a mobile phone receiver(D1-receiver) for the receiver decoder is determined. In a decision step702, the MPN checks whether the D1-receiver is ready to receiveEMM_(D1). If the D1-receiver is not ready then EMM_(D1) is buffered atthe emitter point of the MPN in step 703. Subsequently a decision step704 checks to see if EMM_(D1) is still valid, e.g., if a date ofvalidity for EMM_(D1) might have expired. In case EMM_(D1) is not valid,then a new EMM_(D1) is obtained in step 705 and step 700 executed again.In case EMM_(D1) is found to be valid, then the decision step 702 isperformed again.

If at an issue of step 702 the D1-receiver is found to be ready, thenEMM_(D1) is transmitted to the D1-receiver over the MPN in a step 706,and buffered in the D1-receiver in step 707. In a decision step 708 itis checked whether the receiver decoder D1 is ready to retrieve EMM_(D1)from the D1-receiver. If this is not the case then EMM_(D1) remains inbuffer with the D1-receiver. In the affirmative, EMM_(D1) is retrievedfrom the D1-receiver by the D1 receiver decoder in a step 709.Subsequently a confirmation of reception for EMM_(D1) is returned to theemitter point in step 710, e.g., using the MPN.

Having described preferred embodiments of the invention with referenceto the accompanying drawings, it is to be understood that the inventionis not limited to these precise embodiments and that various changes andmodifications could be effected therein by a person skilled in the artwithout departing from the spirit or scope of the invention as definedin the appended claims.

1. A method for distributing a message from a message administrationservice to a subscriber receiver decoder of a digital multimedianetwork, the method comprising: transferring a determined message for adetermined receiver decoder from the message administration service to apoint to point communication system distinct from the multimedianetwork, the determined message comprising an Entitlement ManagementMessage (EMM), determining a destination poin address of a receiver inthe point to point communication system, corresponding to the determinedreceiver decoder, buffering the determined message in the point to pointcommunication system, retrieving at the determined receiver decoder thedetermined message from the receiver.
 2. The method from claim 1,further comprising: buffering the determined message at an emitter pointin the point to point communication system, corresponding to the messageadministration service, generating a siganl of availability at thereceiver, triggering for emission fo the determined message on receptionof the signal of availaibility, emitting the determined message to thereceiver.
 3. The method according to claim 1, further comprisingreceiving at the receiver the determined message, buffering at thereceiver the determined message.
 4. The method according to claim 1,further comprising: generating a confirmation of receipt at thereceiver, emitting the confirmation of receipt to the emitter point. 5.The method according to claim 4, in which the confirmation of receiptcomprises one or a plurality of items of additional information from thefollowing set: a status of the receiver decoder, a status of a daughtersmartcard used with the receiver decoder, a version number of an elementof the receiver decoder.
 6. The method according to claim 5, furthercomprising: extracting an item of additional information from theconfirmation of receipt, evaluating the item of additional informationto determine a legal status of the receiver decoder.
 7. The methodaccording to claim 1, in which the point to point communicaiton systemis a mobile phone network.
 8. The method according to claim 1, themessage administration service being comprised in a SubscriberAuthorization System.
 9. A method for receving a determined EntitlementManagement Message (EMM) at a determined subscriber receiver decoder ina digital multimedia network, the determined subscriber receiver decoderbeing enabled to receive information through a mobile phonecommunicaiton network distinct of the digital multimedia network, themethod comprising: receiving in a mobile phone modem of the receiverdecoder a message containint at least the determined EMM, the messagebeing addressed specifically to the mobile phone modem of the determinedreceiver decoder, storing at least the EMM in a storage of the mobilephone modem.
 10. The method according to claim 9, further comprisingretrieving the EMM from the storage into the determined receiverdecoder.
 11. A receiver decoder for a digital multimedia network, thereceiver decoder comprising: a mobile phone modem operatively connectedto the receiver decoder, a destination point address uniquely attributedto the mobile phone modem, a storage space in the mobile phone modem tostore at least an Entitlement Management Message (EMM).
 12. The receiverdecoder according to claim 11, wherein the mobile phone modem mayreceiver the EMM from the mobile phone network and store the EMMindependent of a status of the receiver decoder.
 13. The methodaccording to claim 2, further comprising: receiving at the receiver thedetermined message, buffering at the receiver the determined message.14. The method according to claim 2, further comprising: generating aconfirmation of receipt at the receiver, emitting the confirmation ofreceipt to the emitter point.
 15. The method according to claim 3,further comprising: generating a confirmation of receipt at thereceiver, emitting the confirmation of receipt to the emitter point.